流图层

创建流图层

使用 URI 创建流图层

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//Must be on the QueuedTask
var url = "https://geoeventsample1.esri.com:6443/arcgis/rest/services/AirportTraffics/StreamServer";
var createParam = new FeatureLayerCreationParams(new Uri(url))
{
  IsVisible = false //turned off by default
};
var streamLayer = LayerFactory.Instance.CreateLayer<StreamLayer>(createParam, map);

//or use "original" create layer (will be visible by default)
Uri uri = new Uri(url);
streamLayer = LayerFactory.Instance.CreateLayer(uri, map) as StreamLayer;
streamLayer.SetVisibility(false);//turn off

使用定义查询创建流图层

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//Must be on the QueuedTask
var url = "https://geoeventsample1.esri.com:6443/arcgis/rest/services/AirportTraffics/StreamServer";
var lyrCreateParam = new FeatureLayerCreationParams(new Uri(url))
{
  IsVisible = true,
  //At 2.x - DefinitionFilter = new CIMDefinitionFilter()
  //{
  //  DefinitionExpression = "RWY = '29L'",
  //  Name = "Runway"
  //}
  DefinitionQuery = new DefinitionQuery(whereClause: "RWY = '29L'", name: "Runway")
};

var streamLayer = LayerFactory.Instance.CreateLayer<StreamLayer>(lyrCreateParam, map);

使用简单渲染器创建流图层

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var url = @"https://geoeventsample1.esri.com:6443/arcgis/rest/services/LABus/StreamServer";
var uri = new Uri(url, UriKind.Absolute);
//Must be on QueuedTask!
var createParams = new FeatureLayerCreationParams(uri)
{
  RendererDefinition = new SimpleRendererDefinition()
  {
    SymbolTemplate = SymbolFactory.Instance.ConstructPointSymbol(
                        ColorFactory.Instance.BlueRGB,
                        12,
                 SimpleMarkerStyle.Pushpin).MakeSymbolReference()
  }
};
var streamLayer = LayerFactory.Instance.CreateLayer<StreamLayer>(
                    createParams, map);

为最新观测值设置唯一值渲染器

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var url = @"https://geoeventsample1.esri.com:6443/arcgis/rest/services/AirportTraffics/StreamServer";
var uri = new Uri(url, UriKind.Absolute);
//Must be on QueuedTask!

var createParams = new FeatureLayerCreationParams(uri)
{
  IsVisible = false
};
var streamLayer = LayerFactory.Instance.CreateLayer<StreamLayer>(
                    createParams, map);
//Define the unique values by hand
var uvr = new CIMUniqueValueRenderer()
{
  Fields = new string[] { "ACTYPE" },
  UseDefaultSymbol = true,
  DefaultLabel = "Others",
  DefaultSymbol = SymbolFactory.Instance.ConstructPointSymbol(
              CIMColor.CreateRGBColor(185, 185, 185), 8, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
};

var classes = new List<CIMUniqueValueClass>();
//add in classes - one for ACTYPE of 727, one for DC 9
classes.Add(
  new CIMUniqueValueClass() {
        Values = new CIMUniqueValue[] {
              new CIMUniqueValue() { FieldValues = new string[] { "B727" } } },
        Visible = true,
        Label = "Boeing 727",
        Symbol = SymbolFactory.Instance.ConstructPointSymbol(
              ColorFactory.Instance.RedRGB, 10, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
});
classes.Add(
  new CIMUniqueValueClass()
  {
    Values = new CIMUniqueValue[] {
              new CIMUniqueValue() { FieldValues = new string[] { "DC9" } } },
    Visible = true,
    Label = "DC 9",
    Symbol = SymbolFactory.Instance.ConstructPointSymbol(
              ColorFactory.Instance.GreenRGB, 10, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
  });
//add the classes to a group
var groups = new List<CIMUniqueValueGroup>()
{
  new CIMUniqueValueGroup() {
     Classes = classes.ToArray()
  }
};
//add the groups to the renderer
uvr.Groups = groups.ToArray();
//Apply the renderer (for current observations)
streamLayer.SetRenderer(uvr);
streamLayer.SetVisibility(true);//turn on the layer

流图层设置和属性

查找所有可识别轨迹的流图层

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var trackAwareLayers = MapView.Active.Map.GetLayersAsFlattenedList()
                           .OfType<StreamLayer>().Where(sl => sl.IsTrackAware)?.ToList();

确定流图层类型

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//spatial or non-spatial?
if (streamLayer.TrackType == TrackType.AttributeOnly)
{
  //this is a non-spatial stream layer
}
else
{
  //this must be a spatial stream layer
}

检查流图层连接状态

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if (!streamLayer.IsStreamingConnectionOpen)
  //Must be on QueuedTask!
  streamLayer.StartStreaming();

开始和停止流式传输

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//Must be on QueuedTask!
//Start...
streamLayer.StartStreaming();
//Stop...
streamLayer.StopStreaming();

删除所有当前和以前的观察结果

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//Must be on QueuedTask!
//Must be called on the feature class
using (var rfc = streamLayer.GetFeatureClass())
  rfc.Truncate();

获取跟踪 ID 字段

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if (streamLayer.IsTrackAware)
{
  var trackField = streamLayer.TrackIdFieldName;
  //TODO use the field name
}

获取曲目类型

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var trackType = streamLayer.TrackType;
switch(trackType)
{
  //TODO deal with tracktype
  case TrackType.None:
  case TrackType.AttributeOnly:
  case TrackType.Spatial:
    break;
}

设置要存储在内存中的先前观测值的最大计数

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//Must be on QueuedTask
//Set Expiration Method and Max Expiration Count
if (streamLayer.GetExpirationMethod() != FeatureExpirationMethod.MaximumFeatureCount)
  streamLayer.SetExpirationMethod(FeatureExpirationMethod.MaximumFeatureCount);
streamLayer.SetExpirationMaxCount(15);
//FYI
if (streamLayer.IsTrackAware)
{
  //MaxCount is per track! otherwise for the entire layer
}

设置要存储在内存中的先前观测值的最长期限

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//Must be on QueuedTask
//Set Expiration Method and Max Expiration Age
if (streamLayer.GetExpirationMethod() != FeatureExpirationMethod.MaximumFeatureAge)
  streamLayer.SetExpirationMethod(FeatureExpirationMethod.MaximumFeatureAge);
//set to 12 hours (max is 24 hours)
streamLayer.SetExpirationMaxAge(new TimeSpan(12,0,0));

//FYI
if (streamLayer.IsTrackAware)
{
  //MaxAge is per track! otherwise for the entire layer
}

通过 CIM 设置各种流图层属性

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//The layer must be track aware and spatial
if (streamLayer.TrackType != TrackType.Spatial)
  return;
//Must be on QueuedTask
//get the CIM Definition
var def = streamLayer.GetDefinition() as CIMFeatureLayer;
//set the number of previous observations, 
def.PreviousObservationsCount = (int)streamLayer.GetExpirationMaxCount() - 1;
//set show previous observations and track lines to true
def.ShowPreviousObservations = true;
def.ShowTracks = true;
//commit the changes
streamLayer.SetDefinition(def);

;